Question: Khan.scratchpad.disable(); Nadia sells magazine subscriptions and earns $$4$ for every new subscriber she signs up. Nadia also earns a $$29$ weekly bonus regardless of how many magazine subscriptions she sells. If Nadia wants to earn at least $$39$ this week, what is the minimum number of subscriptions she needs to sell?
Solution: To solve this, let's set up an expression to show how much money Nadia will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Nadia wants to make at least $$39$ this week, we can turn this into an inequality. Amount earned this week $\geq $39$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $39$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $4 + $29 \geq $39$ $ x \cdot $4 \geq $39 - $29 $ $ x \cdot $4 \geq $10 $ $x \geq \dfrac{10}{4} \approx 2.50$ Since Nadia cannot sell parts of subscriptions, we round $2.50$ up to $3$ Nadia must sell at least 3 subscriptions this week.